McCarthy, R-Calif., who has climbed quickly since arriving in Congress in 2007, seemed likely to become majority leader when House Republican lawmakers meet privately Thursday to elect their leadership for the rest of this year.

"I have the courage to lead but the wisdom to listen," McCarthy, 49, told a reporter Wednesday. As the party's vote counter and the chief recruiter of 2010 candidates who helped the GOP capture House control that November, he said, "I understand people's frustrations."

Those frustrations seem plentiful as Republicans continue debating the meaning of Cantor's startling loss to a political neophyte last week in what was supposed to be a routine GOP primary in his Richmond, Virginia, area district. The next day, Cantor announced he would step down as majority leader on July 31, setting off the scramble for leadership jobs.

The contest to replace McCarthy as whip seemed a tough call among three rivals, with added doses of unpredictability because personal relationships matter and because Thursday's voting is by secret ballot.

The contenders are Roskam; McCarthy's deputy whip; Steve Scalise of Louisiana, leader of an organization of House conservatives; and Marlin Stutzman of Indiana, a second-term lawmaker who may attract votes from tea party lawmakers who feel Scalise has been too cooperative with party leaders.

Challenging McCarthy in a long-shot bid was second-term Rep. Raul Labrador of Idaho. A conservative rebel who refused to back John Boehner, R-Ohio, as speaker on the first day of the new Congress in 2013, Labrador, 46, said the current leadership team must be changed.

"If you vote for the status quo tomorrow, you will prove that we are still not listening" to disgruntled voters, Labrador told fellow Republicans in a closed-door meeting Wednesday, according to remarks distributed by his staff. Such a result would imperil GOP efforts to win Senate control this November and capture the White House in 2016, Labrador said.

Though that sentiment was widely shared among some of the more conservative GOP lawmakers, many others said now was the time for calm. That — and lightning-fast moves by McCarthy last week to solidify support — seemed to make the majority leader race uncompetitive.

"Given the way Cantor is going out, it's important to show a little bit of stability," said Rep. John Campbell, R-Calif., who said he backed McCarthy.

A McCarthy victory would elevate the genial one-time deli owner who became a congressional aide and then a California state legislator before his election to the House from Bakersfield, California. McCarthy has been close to Cantor, though his 72 percent rating by the American Conservative Union for key votes last year was less than Cantor's 84 percent.

Several factors were roiling the race for whip, including regional sensitivities.

With McCarthy's expected ascension and both Boehner and No. 4 GOP leader Cathy McMorris Rodgers of Washington state unchallenged, that left only the No. 3 job available for a lawmaker not from a state President Barack Obama carried in 2012. In a nod to that, Roskam promised colleagues that if he became whip, he would appoint a deputy from a Republican-leaning state.